It's the split sending shockwaves through Hollywood.
The picture-perfect Cruise-Cruz couple is calling it quits!

"She's a sweetheart," Tom told us last Fall. "She's a beautiful lady, and it's fun -- she's fun." But now we're learning inside details on the breakup, officially confirmed last night by Tom's new spokesperson, his sister Lee Anne Devette.

Tom and Penelope met in 2001 while filming "Vanilla Sky." People magazine senior editor Jess Cagle has been tracking their relationship, which has lately been showing signs of change.

"A source tells me they never spent any time together," says Cagle.

Just last night, Tom was spotted flying solo, signing autographs in New York, while in February, at this year's Golden Globes, Tom walked the red carpet with his mother, not Penelope. And he was solo again at the Independent Spirit Awards a few weeks ago, where he told "Extra" that Penelope was tending to her ailing father in Spain.

Cagle tells "Extra" the couple actually split back in January, and the biggest issue was their hectic careers. Tom spent months away in Japan filming "The Last Samurai," then Penelope was away in Morocco for her own movie.

"In reality, these are two busy people," says Cagle. "One of whom is a single father, just trying to make it work."

In fact, Penelope told "Extra" about their difficult juggling act, when they attended the "Last Samurai" premiere, saying, "we both work a lot because we love working."

Tom of course has his own important family commitments. He's devoted to the two kids he shares with Nicole Kidman, with whom he remains friendly. Very friendly, according to Cagle: "I wouldn't be surprised if Tom got back with Nicole. He's very fond of her."

As for Tom and his most recent lady, Penelope, their camps both
say the split was amicable, and they too remain good friends.